vitamin D

Metabolism

Source

- ingested in diet

- absorbed in small intestine / duodenum

- under control of vitamin D

Excretion

- through kidney

- majority is reabsorbed

- under control of vitamin D

Storage

- 99% stored in bone

Source

- produced by parathyroid glands

1/3 caucasian women > 64

Insufficient bone mass at time of skeletal maturity

- peak bone mass is achieved at age 25

Rapid loss of bone after menopause

Low body weight / weight loss / history of smoking / steroids

Type 1

- postmenopausal

- high turnover / osteoclast mediated

- F x 6